Markdown was invented in 2004 by John Gruber with a single purpose: to let people write plain text that can be converted to HTML without writing any HTML tags by hand. Thirty years of developer tooling later, Markdown is everywhere. README files on GitHub, blog posts in static site generators, documentation in almost every framework, chat messages in Slack and Discord, and notes in Notion and Obsidian all use Markdown or a dialect of it.
At some point you will need the actual HTML that Markdown represents. This guide explains how Markdown and HTML relate, how the conversion works element by element, and how to convert any Markdown file to HTML in seconds.
What Is Markdown?
Markdown is a lightweight markup language that uses simple punctuation to indicate formatting. A line that starts with a hash character becomes a heading. Text surrounded by two asterisks becomes bold. Text surrounded by one asterisk becomes italic. A line that starts with a hyphen becomes a bullet list item.
Because Markdown uses only plain ASCII characters for its syntax, it is readable as-is, without any rendering. This is the key design goal: a Markdown source file should be easy to read even before it is converted to HTML.
What Is HTML?
HTML is HyperText Markup Language, the language all web browsers understand. It uses angle-bracket tags to describe the structure and meaning of content. Headings are wrapped in h1 through h6 tags. Paragraphs use the p tag. Bold text uses the strong tag. Links use the a tag with an href attribute.
Browsers do not understand Markdown. They understand HTML. So whenever Markdown content needs to appear in a browser (on a website, in a web app, in an email, in a CMS), it must first be converted to HTML.
How Markdown Maps to HTML
Every Markdown element has a direct HTML equivalent. Understanding this mapping helps you predict exactly what HTML will be produced when you convert.
A heading with one hash becomes an h1 tag. Two hashes become an h2 tag. Three hashes become h3, and so on down to h6.
Text surrounded by double asterisks (or double underscores) becomes a strong tag, which browsers display as bold by default.
Text surrounded by single asterisks (or single underscores) becomes an em tag, which browsers display as italic by default.
A line starting with a hyphen, an asterisk, or a plus sign becomes a list item inside an unordered list (ul) element. A line starting with a number and a period becomes a list item inside an ordered list (ol) element.
A link written as text in square brackets followed by a URL in round brackets becomes an anchor tag with the href attribute set to the URL.
An image written as an exclamation mark followed by alt text in square brackets followed by an image URL in round brackets becomes an img tag.
A paragraph is created automatically from any block of text separated by blank lines. The converter wraps it in a p tag.
Inline code wrapped in single backticks becomes a code tag. Code blocks (indented by four spaces or wrapped in triple backticks in GitHub Flavoured Markdown) become a pre tag containing a code tag.
Horizontal rules (three hyphens, asterisks, or underscores on their own line) become an hr tag.
Blockquotes (lines starting with a greater-than sign) become a blockquote tag.
Why Convert Markdown to HTML?
Pasting into a CMS that requires HTML. Many content management systems, email builders, and newsletter platforms accept HTML but not Markdown. Writing in Markdown and converting gives you the best of both worlds: easy authoring and compatible output.
Embedding documentation in a webpage. If you maintain documentation in Markdown files but need to display them on a website without a static site generator, converting to HTML first lets you include the content in any page template.
Building emails. HTML emails are notoriously tedious to write by hand. Writing the content in Markdown and converting it to HTML gives you a starting point that you can then style with inline CSS.
Archiving. An HTML file is more universally readable than a Markdown file for non-technical audiences. Converting before sharing ensures the recipient can open the document in any web browser.
Debugging a Markdown parser. If your static site generator or documentation tool is producing unexpected HTML, converting the Markdown manually in a tool lets you verify what the raw conversion should produce.
GitHub Flavoured Markdown
The original Markdown specification covers the elements described above. GitHub Flavoured Markdown (GFM) adds several extensions that are now widely supported:
Tables: rows of cells separated by pipe characters, with a separator row of hyphens to define the header.
Strikethrough: text surrounded by two tildes becomes a del tag.
Task lists: list items starting with a checkbox syntax like a hyphen followed by square brackets and a space become interactive checkboxes in rendered form.
Fenced code blocks: blocks delimited by triple backticks (instead of indentation) with an optional language name for syntax highlighting.
Autolinks: bare URLs are automatically converted to clickable links.
The DevHexLab Markdown to HTML tool supports GitHub Flavoured Markdown in addition to the core specification.
How to Use the DevHexLab Markdown to HTML Tool
Open the tool at /tools/text/markdown-to-html. Paste your Markdown content into the left panel. The HTML output appears in the right panel in real time.
You can also preview how the rendered HTML will look in a browser by switching to the preview tab. This shows you the final visual output with headings, bold text, lists, and links all styled as the browser would display them.
When the output looks correct, click Copy to grab the HTML or Download to save it as an .html file.
What Gets Added Around the Converted HTML?
The converter produces the inner HTML for your content, meaning the actual tags for your headings, paragraphs, and lists. It does not automatically add the full page shell (the html, head, and body tags) unless you specifically need a complete standalone document.
If you need a complete HTML document, you can wrap the converter output in the standard page structure: the DOCTYPE declaration, the html tag, a head tag with a title and charset meta tag, and a body tag. The converter output goes inside the body tag.
Common Pitfalls When Converting Markdown to HTML
Hard line breaks. In standard Markdown, a single line break does not produce a br tag in HTML. You need either a blank line (to start a new paragraph) or two spaces at the end of a line (to force a line break). If your converted HTML looks like it is missing line breaks, this is usually the cause.
Nested lists. Nested lists require consistent indentation in the Markdown source. Inconsistent indentation can produce incorrect nesting in the HTML output.
Raw HTML in Markdown. Most Markdown processors allow you to write raw HTML tags inside a Markdown file. These pass through to the HTML output unchanged. This is useful for elements Markdown does not support, but it means the converter trusts whatever HTML you include, so take care if the source is untrusted.
Special characters. Characters that have meaning in HTML (the ampersand, less-than, and greater-than signs) are automatically escaped by the converter when they appear outside of HTML contexts. Text that says 1 < 2 in Markdown will correctly produce 1 < 2 in the HTML output.
Frequently Asked Questions
Does Markdown support tables?
Standard Markdown does not include table syntax. GitHub Flavoured Markdown and many extended specifications do. The DevHexLab Markdown to HTML tool supports GFM-style tables using pipe characters and hyphen separator rows.
Can I add CSS to styled Markdown-converted HTML?
Yes. The HTML produced by the converter uses standard semantic tags (h1, p, ul, blockquote, etc.) that you can target with any CSS stylesheet. Add a stylesheet link in the head of your document or apply inline styles as needed.
What is the difference between a Markdown renderer and a Markdown to HTML converter?
A renderer displays the visual output of Markdown inside an application (like how GitHub shows README files). A converter produces the raw HTML source code. The DevHexLab tool does both: it converts to HTML and also provides a preview of the rendered result.
Is Markdown to HTML conversion lossless?
For all elements defined in the Markdown specification, yes. Comments in HTML have no Markdown equivalent, and conversely, Markdown comments (HTML comment syntax) pass through to the HTML output unchanged. Markdown flavour extensions (like GFM tables) may not be supported by all converters.
Write in Markdown, Ship in HTML
Markdown is the fastest way to write formatted content. HTML is what the web requires. The DevHexLab Markdown to HTML tool bridges the gap instantly, letting you stay in the comfortable plain-text authoring experience while producing clean, valid HTML for wherever you need it. Paste your Markdown, copy the HTML, and move on.